Nutrition In Sport - Staying Healthy While You Train
Athletes undergoing strenuous training and competition have greater nutritional needs than the sedentary population. Obtaining adequate nutrients will ensure maximal recovery time and lower rates of injuries and illnesses.
Increased perspiration associated with sport, particularly endurance sport, can lead to an increased loss of minerals and potentially set us up for nutritional deficiency diseases as the nutrient intake sufficient for the general population is not always sufficient for athletes.
Athletes lose more electrolytes such as calcium, magnesium, potassium and sodium due to perspiration.
Minerals are needed in higher amounts and supplementation can ensure adequate intake is achieved.
Optimal bone strength is important for all athletes. Stress fractures can bring an abrupt finish to years of training because the athlete’s diet is not providing the necessary nutrients they require to maintain the strength of their bones.
The following table shows a few of the nutrients and their role in sport and exercise.
Table 1 Nutrients in Sport
Nutrient
Importance to Athlete Health
Notes
Calcium
Ninety nine percent of our calcium is found in our bones, the other one percent is necessary for many functions, including nerve transmission and muscle contraction. The level of calcium in our blood is kept within very narrow limits and if our dietary intake is inadequate or our calcium loss is too great calcium is drawn from our bones. This is what we call Osteoporosis.
A deficiency of calcium and magnesium can cause muscle tremors and cramp. Numerous studies over the past 20 years have shown athletes in a wide variety of sports to have deficient intakes of calcium. This can be further complicated by a high protein intake, leading to increased loss of calcium.
Chromium
Is essential for human health and is required for insulin to work efficiently. Insulin is required for the transport of sugar and amino acids into the cells.
Iron
For the casual athlete training under 4 hours per week, iron deficiency is no more of a concern than for a sedentary counterpart. For athletes, training aerobically for 6+ hours per week, iron deficient anemia is common
Athletes have been shown to turn over iron stores more quickly than non-athletes do. Considering the severe neurological effects of anemia on the young, children and teens engaging in rigorous sports should be counselled to assure adequate dietary iron.
Magnesium
Necessary co-factor and stimulator of enzymes for the body’s production of energy from fatty acids and bone remineralisation. Important mineral for muscle relaxation and works in combination with calcium, potassium and sodium. A deficiency of these nutrients can lead to cramp, fatigue, nausea. Chronic deficiency can lead to osteoporosis risk and anemia.
Magnesium is equally as important as calcium. Magnesium deficiency leads to a decreased concentration of the active form of vitamin D which is essential for calcium absorption. Athletes are known to lose magnesium via sweat and urine. The best way to supplement with magnesium is with plant derived minerals.
Potassium
Is necessary for muscle contraction. Potassium and other minerals lost in perspiration and urine during exercise. Deficiency may result in fatigue.
Will benefit the sports person when low levels are present in the body. May have role in increasing lean muscle mass and reducing body fat.
Selenium
Glutathione (GSH) is a free radical scavenging tripeptide made up of glutamine, cysteine and glycine. It is concentrated at the lining of the GI tract and lungs, in the liver and in skeletal muscle. The mineral selenium is an essential unit to GSH production. Reduction of muscular GSH is inversely correlated with cellular damage from prolonged exercise.
Research has shown selenium to benefit athletes in immune function and repair of cellular damage. Has a protective effect against cardiomyopathy heart disease.
Many athletes supplementing with Selenium report reduced muscle soreness following exercise. Recommended intake is around 300mcg / day for protective functions of Selenium.
Sodium
Required for normal muscle function and regulation of electrolytes in the cells. Large quantities lost through perspiration and sweating.
Deficiencies lead to muscle cramps, weight loss and general weakness.
Zinc
Any physical demands on the body increase the need for zinc due to an increased rate of muscle utilisation and loss via perspiration and urine. Tissues that are zinc deficient will not recover after normal resting periods, leaving muscles and connective tissue prone to injuries
Heavy losses of zinc are caused by sweating. A common zinc deficiency in athletes may lead to muscle weakness and anorexia. Zinc is also important to the athlete as exercise and other forms of stress alter zinc metabolism and stimulate zinc losses.
Co-Enzyme Q10
Is essential for energy production. Co-Q10 plays a crucial role in the production of energy in every cell of the body by helping to transfer electrons in the energy cycle within the mitochondria. It is a powerful antioxidant and is important for good immunity and heart function.
Exercise causes high energy turnover increasing our requirement for Co-Enzyme Q10. Co-Q10 assists athletes by increasing the body’s tolerance to exertion and strengthens the cardiovascular system.
Glucosamine
Glucosamine is the key regulator of connective tissue and repair (ie tendons, ligaments, cartilage). Glucosamine stimulates the synthesis of new cells, stimulating new cartilage production and collagen synthesis and experimentally damaged cartilage
Along with Chondroitin it is recommended for treatment of sports injuries related to joints and connective tissue.
Several double-blind studies have proven a relationship between Glucosamine, Chodroitin and pain reduction and improvement in mobility.
Chondroitin
Is found concentrated in connective tissues and stimulates synthesis of endogenous glucosamine by cartilage cells.
Vitamin C / Bioflavenoids
Maintain collagen tissue, muscles, ligaments, tendons. Help injuries to heal. Vitamin C is burned up under prolonged stress due to exercise and needs to be consumed regularly..
Vitamin C builds resistance which ensures athletes’ lost training time is minimised.
Alpha Lipoic Acid (ALA) & Acetyl L Carnitine (ALC)
Carry fatty acids into the energy producing part of the cell (mitochondria) for energy production. ALA acts as an antioxidant recycling other nutrients such as Vitamin C, E & raises the levels of Glutathione – required for the conversion of carbohydrates into energy.
Early studies indicate that they may have a role in reducing exercise-induced oxidative stress – i.e. lessen the damage of free radicals caused by exercise.
Vitamin B1 (Thiamine)
Essential for energy production from food
Athletes require more Thiamine than general population because of their much higher turnover of energy
Vitamin B2 (Riboflavin)
Helps mitochondria produce energy
Food processing destroys up to 80% of Vitamin B2
Even moderate exercise increases B2 requirements in healthy women
Studies show even well fed athletes can be deficient in Vitamin B2
Vitamin B3 (Niacin, Niacinamine)
Required for conversion of glycogen and fatty acids, carbohydrates and protein to energy
Athletes require more Niacin than sedentary people
Vitamin B6 (Pyridoxine)
Essential for the breakdown of muscle glycogen for fuel
Requirements for Vitamin B6 increase as protein requirements increase and energy expenditure increases
Vitamin B5 (Pantothenic Acid)
Supplementation with 2 grams daily in elite distance runners showed reduced lactate build up by 17% and reduced oxygen consumption
Vitamin D
Improves absorption and utilisation of calcium and phosphorus required for strong, resilient bone tissue.
Vitamin E
Aerobic exercise places additional demands on the molecular free radical scavengers of the body. This occurs in the mitochondrial membranes of the cell. Vitamin E is known to be a potent scavenger of cellular membrane free radicals.
Research has shown that athletes do not use more vitamin E, but do show less cellular damage by ingesting higher amounts.
May have significant benefit to athletes at high altitudes, where oxidative stress is greater – resulting in a higher anaerobic threshold. Low levels also associate with muscle weakness.
Folate
Essential for amino acid metabolism
Deficiency inhibits the growth of new cells especially the rapidly changing muscle cells and blood cells of athletes
Protein - Amino Acids
Endurance athletes need the additional proteins for different reasons than strength athletes. Endurance athletes primarily use protein for maintaining aerobic metabolism as opposed to the increased tissue repair needs in strength athletes.
When intake is inadequate, the body takes the needed proteins from lean tissue giving over-trained endurance athletes a 'gaunt' appearance. Protein deficit also gives athletes poorer recovery times and delayed wound healing.
Essential Fatty Acids
The EFA’s shorten substantially the time required for the recovery of fatigued muscles after exercise, by facilitating the conversion of lactic acid to water and carbon dioxide.
For optimum sports nutrition, there are two essential fatty acids (EFA’s) that our bodies can’t make: linoleic acid (omega 6) and linolenic acid (omega 3) which are required in our daily diet and are converted to more active compounds.
The EFA’s are also the precursors of a family of substances, the hormone-like, short lived prostaglandins, which regulate many functions of all tissues on a moment to moment basis. There are ‘good’ and ‘bad’ prostaglandins and the balance may be influenced by the amount of essential fatty acids we consume. More protein and EFA consumption will lead to a reduced inflammation and pain response, improved endurance and oxygen uptake; while excess carbohydrates and ‘bad fats’ will do the opposite and be detrimental for the athlete.
Antioxidants
Exercise increases free radical production which causes damage to muscle cells and is the major cause of continued muscle soreness and weakness felt for days after exercise. Antioxidant nutrients provide protection against free radical damage to which athletes have greater exposure.
Antioxidants include: Vitamin A (as betacarotene), C, E, Selenium (as selenomethionine), CoQ10 - to name just a few.
Ideal sources are from fresh fruit an vegetables and supplements.
What Our Experts Say
All of our experts agree that it is beyond dispute that if you have an unhealthy diet it will contribute not only towards muscle cramps but in the long term to more serious health conditions - regardless of how much or how hard you exercise.
Prevention in terms of nutrition comes down to consuming a mostly Fresh Food Diet that is high in minerals and avoiding ‘Empty’ foods that are high in sugar, low in minerals and introduce toxins and antibiotics into our systems.
Fast food of any type, fried food, processed or refined carbohydrates (such as cakes, biscuits and most types of bread), alcohol and excessive amounts of caffeine are all examples.
In terms of cramping, eating the wrong food does the following:
1) Reduces our muscles’ energy reserves and makes cramping more likely
2) Deprives the muscles of minerals required to relax and contract the muscles – particularly Calcium, Magnesium, Phosphorous and Potassium
3) Introduces toxins (preservatives, food colouring and flavour enhancers) that have a stimulatory effect on the muscles and tend to inhibit the relaxation response.
Kinesiologist and Osteopath, David Wells explains it this way: “When you eat ‘fast’ or ‘junk’ food you are depriving your body of the right fuel but also increasing overall toxicity with flavour enhancers and preservatives which are stimulatory to the brain and therefore tend to produce increased muscle tone (i.e. switching on the muscle contraction), making it more likely that you will cramp.”
“All of these toxins have to pass out through the liver for detoxification and therefore reduce your energy output because the liver burns up your energy reserves trying to detoxify you. This results in you feeling tired and with less energy for your muscles to work."
Sports nutritionist Richard Renton agrees, "Being an athletic trainer and having worked with teams for a long time, after starting with a new team I could tell you after 2 weeks who’s going to get cramps & who’s not - poor diet or a good diet, their habits, whether they sweat profusely, whether they take care of themselves or not, you can tell. If they're drinking a litre of fizzy pop before they work out, and if that’s their only method of drinking water, that’s going to create a lot of problems.”
So a good diet with plenty of fresh food is something everyone who suffers regular cramps should take notice of. Gone are the days, particularly as we get older when you can eat anything you like because you're able to burn off the calories.
Athletes who used to try this suffered worse problems than cramps. Many elite endurance athletes of the 90's frequently suffered 'mystery viruses' and many athletes today frequently suffer severe fatigue. Poor nutrition, including a lack of minerals and antioxidants, will lead to a depleted immune system ad a host of nutritional deficiency diseases.
If you're not eating a healthy diet and exercising regularly and suffering cramps, you're getting the early warning signs of worse things to come, so "clean up your act".
Recommendations
It’s quite obvious that an athlete or anyone who exercises regularly and sweats is going to have a higher nutrient requirement and this means three things in terms of a regular diet:
1) Consuming a diet high in fresh fruit and vegetables and as much fresh, whole food (meat, dairy, grains, fruits and nuts) as possible.
2) Avoiding processed and fast food – which will actually cause problems for the athlete in terms of too taking in too many trans fatty acids, omega 6 fatty acids and free radicals (in the form of preservatives, food colouring and flavouring etc) and very few minerals.
3) Consider a supplement program that, at the very least, includes minerals.
In The Ultimate Cramp Busting Guide our nutritional and sports experts will give you even more detailed suggestions on food types, suggested meal plans and on the major minerals and nutrients associated with maintaining electrolyte balance and preventing cramps.
